February 4, 2014

The Curiosity Mars rover is to try to drive over a one metre-high dune.
The sand bank is currently blocking the robot's path into a small valley and a route with fewer of the sharp rocks that lately have been making big dents in the vehicle's aluminium wheels.
US space agency engineers will take no risks, however. The rover will be commanded initially to climb only part way up the dune to see how it behaves.
The team is mindful that NASA's Spirit rover was lost in a sand trap in 2009.
And the Opportunity rover, which has just celebrated 10 working years on the planet, very nearly went the same way in 2005 when it became stuck for several weeks in a deep dirt pile later dubbed "Purgatory Dune".